His video is flawed. Couple of things.
First of all he is getting unfiltered air into his air box that is coming from a dirtier source. Not good for turbos, esp with being how small the compressor wheels are.
Second, it doesn't matter how much air volume you pick up. If the turbos cannot use it, it is a moot point.
Third, you will never be able to get intake air temps (to the box) lower than ambient without a some type of chemical cooler or physical cooler.
Fourth, he doesn't "document" anything. The test needs to be get done in the same conditions, same speed, and same throttle input. He claimed there are a couple of degrees difference. I saw a quick 123 degrees when he gave it some gas after, then the IAT's quickly bounces back into the 130's completely negating the reason. Now it if it dropped it 10 to 15 degrees and maintained it he might be on to something. It thermally cannot maintain it.
In the real world this will do nothing. The limiting factor is the stock IC. You are introducing "more" dirty ambient temp air into an environment that it cannot be used because of turbo size. No matter how much you increase the volume of ambient air temp it has zero effect on how effective the stock IC is. Only air temp it does. If it is colder the IC works better, if it is hotter...it works worse.